title: Perinatal and postnatal expression of Cav1.3 α1D Ca²⁺ channel in the rat heart.
abstract: The novel Cav1.3 (α1D) L-type Ca²⁺ channel plays a significant role in sinoatrial (SA) and atrioventricular (AV) nodes function and in atrial fibrillation. However, the characterization of α1D Ca²⁺ channel during heart development is very limited. We used real-time RT-PCR, Western blotting, and indirect immunostaining to characterize the developmental expression and localization of α1D Ca²⁺ channel in rat hearts. Both protein and mRNA levels of α1D Ca²⁺ channel decreased postnatally. Two forms of α1D Ca²⁺ channel protein (250 and 190 kD) were observed, with the full-length (250 kD) channel protein being predominant in the prenatal stages. Both Western blots and confocal imaging demonstrated that α1D Ca²⁺ channel protein was expressed in both atria and ventricles at fetal and neonatal stages but was absent in the adult ventricles. Interestingly, α1D Ca²⁺ channel was also found at the nucleus/perinucleus of immature but not adult atrial cells. Furthermore, the nuclear staining was reproduced in adult atrial cell line, HL-1 cells, which possess immature properties. The data are first to show that α1D Ca²⁺ channel has unique age-dependent expression profile and subcellular localization in the heart, suggesting a developmental stage-dependent specific function.
authors.affiliation: Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, NY 11209, USA.
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Qu
authors.forename: Eddy
authors.initials: E
authors.lastname: Karnabi
authors.forename: Omar
authors.initials: O
authors.lastname: Ramadan
authors.forename: Yuankun
authors.initials: Y
authors.lastname: Yue
authors.forename: Mohamed
authors.initials: M
authors.lastname: Chahine
authors.forename: Mohamed
authors.initials: M
authors.lastname: Boutjdir
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D006321:Heart / Q000254:growth & development* / Q000502:physiology; D006325:Heart Atria / Q000378:metabolism*; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015220:Calcium Channels; D012333:RNA, Messenger; C093712:Cacna1d protein, rat